1. Field of the Invention
This invention relates to a video signal reproducing apparatus and, more particularly, to a video signal reproducing apparatus for use with a video tape having a longitudinal track having an address signal recorded thereon and successive slant tracks having a video signal recorded thereon and an information signal recorded thereon at predetermined intervals.
2. Description of the Prior Art
In editing a video signal recorded on a video tape, it is important to achieve time related information specifying the distance of movement of the video tape. It is the conventional practice to provide such time related information by employing a time code signal recorded on a longitudinal time code track (LTC). Although this approach is satisfactory when video signal reproduction is performed in a normal mode, it fails to provide any reliable time code signal when the video signal reproduction is performed in a slow mode where the tape speed is too slow to reproduce a reliable time code signal. In fact, any reliable time code signal cannot be obtained when the tape speed is one-fifth or one-tenth of the normal speed at which the video tape moves in a recording mode.
In order to avoid the problem, one approach employs a control signal recorded on another longitudinal time control track (TRC) at predetermined intervals, for example, of one field to update the time related information specified by the last time code signal obtained when the time code signal is still reliable. With this approach, however, the control signal itself becomes too unreliable to update the time related information correctly according to the distance of movement of the video tape when video signal reproduction is performed in a slow mode.
Another approach employs a signal produced at predetermined intervals of the distance of movement of the video tape from a timer roller having a video tape wound therearound at an angle, for example, greater than 180.degree. C. However, this approach creates other problems. First, it requires a space consuming timer roller, resulting in a large-sized apparatus. Second, the timer roller rotates in a frictional manner with respect to the video tape and damages the video tape. In addition, a slippage would occur between the timer roller and the video tape, resulting in an error between the number of rotation of the timer roller and the distance of movement of the video tape to cause inaccurate time related information.
It may also be considered to employ a time code signal recorded on one of the user's bits of each slant video track (TRV). However, this approach reduces the number of the user's bits alloted to users.